The ground-level fountains so popular with the grade-school set can be founts of a rather nasty diarrheal disease caused by the microscopic parasite cryptosporidium.
That's one lesson from a new report from the Centers for Disease Control and Prevention, which found 134 disease outbreaks associated with recreational water in 2007-08, the most recent data available. That's a 72% increase from the previous report and the largest number ever reported in a two-year period.
Those outbreaks resulted in at least 13,966 illnesses. Cryptosporidium was responsible for 60 of the 105 outbreaks that health officials were able confirm in a lab and the largest number of victims, 12,137.
Cryptosporidium causes the diarrheal disease cryptosporidiosis. Both the parasite and the disease are commonly known as "crypto." It can cause watery diarrhea and stomach cramps and sometimes dehydration, nausea, vomiting and fever that last about a week. For most people, it is unpleasant but not dangerous. But in the very young, the old and those with compromised immune systems, it can be more dangerous.
Unlike many illnesses that can be waterborne, such as E. coli, norovirus and shigella, cryptosporidium is relatively resistant to chlorine, the most commonly used disinfectant in water.
"Crypto is pretty tolerant of chlorine," says Michele Hlavsa, chief of CDC's Healthy Swimming Program. At the recommended levels for pools, fountains and water parks, 1 to 2 milligrams of chlorine per liter of water, the parasite can live for three to 10 days, she says.
Between 1997 and 2008, 16 outbreaks linked to fountains were reported to the CDC, 11 caused by crypto. It was only in 2005 that the Food and Drug Administration approved a treatment, so prior to that, very few people were tested for it. It is spread through fecal transmission.
There are ways to kill cryptosporidium protozoa, including ultraviolet light and ozone, but they're both much more expensive than chlorine. Recreational water quality is not regulated at the federal level, but by state or local agencies.
Bad bug
Of 105 confirmed disease outbreaks in pools and fountains,
cryptosporidium was responsible for:
60
Outbreaks
12,137
Illnesses
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